Method and apparatus for threading metal articles



G. E. MIRFIELD METHOD AND APPARATUS FOR THREADING METAL ARTICLES Feb, 23 1926. 1,574,631

Filed April 22, 1922 esheetkshe'et 1 Feb. 23 1926.

G. E. MIRFIEALD' METHOD AND APPARATUS FOR THREADING METAL ARTICLES Filed April 22, 1922 G sheets-sheet 3 A La G. E. MIRFIELEL' METHOD AND APPARATUS FOR THREADING METAL ARTICLES I e Sheets-{Sheet 4 Fi led April 22, 1922 INVENTOR Feb. 23 1926; r 1,574,631

G. E. MIRFIELD METHOD AND APPARATUS FOR THREADING METAL ARTICLES Fild April 22, 1922 6 sheets sheet 5 i i qmu w Jig '51 7/4 q 50 57 ILIVENTOR Feb. 23 1926. 1,574,631

G. E. MIRFIELD METHOD AND APPARATUS FOR THREADING METAL ARTICLES Filed April 22, 1922 6 sheets-Shasta 6 1) ts N Q, o m N N T q m w a m Patented Feb. 23, 1926.

UNITED STATES PATENT OFFICE.

GEORGE E. MIBFIELD, OF-YOUNGSTOWN, OHIO.

METHOD AN D APPARATUS FOR THREADING METAL ARTICLES.

Application filed April 22, 1922. Serial No. 556,114.

and State-of Ohio, have invented a new and useful Improvement in. Methods and Apparatus for Threading-Metal Articles, of which the following is a full, clear, and exact description.

My invention relates to method of andapparatus for performing a plurality of successive mechanical operations u'pon metal articles, and is particularly useful in threading couplings and similar articles.

I have devised a method and apparatus whereby a coupling, for instance, ma be machined from both ends about the axis of the unmachined surface and which may be machine threaded at both ends, with only one centering operation. Furthermore, the machining of one end of one coupling may be effected while the end of another couppling is being machined.- In some instances .three threading or similar operations may be carried out simultaneously. In all cases all the threading or other operations are carried out automatically, with but one bandling of the article;

By the use of my invention, accurate operations may be carried out in a more expeditious manner than by any means heretofore used. y

My invention will be'better understood by reading the following description, taken in connection with the accompanying drawings, in which: 1

Figure 1 is a plan view of a machine emibodylng my invention and for carrying out my method; Figure 2 is a side elevation of that machine; v

Figure 3,is a vertical section on the line III- 111 of Figure 1;

Figure 4 is a section on the line IV-IV of Figure 3;

Figure 4 is a view similar to Figure 4,

showing the intermediate positions of the gear elements 35, 39,40 and 41 when the main turret has been turned through de grees from a rest position;

Figure 4 is-a section of a portion of the machine, the section being taken on the line IV"IV of Figure 4; p v Figure 5 ure 6; we

is a section on line VV of Fig-- Figure 6 is a section on line VIVI of Figure 5;

Figure 7 is a bottom view of operating means; and

Figure 8 is a section on the line VIII- VIII of Figure 2.

Referring to the drawings, Figure 2, the

the turret machine comprises a frame 1 provided with. a base 2 which rests upon pedestals 3 and 4.

The frame 1 is provided atits ends with tap holders 5 and 6. These tap. holders may be of any standard construction, and per se form no part of the present invention. The

head 5 is provided with a collapsible tap 7 which is rotated through a belt 8 driven by a motor 9. The head 6 is likewise provided with a collapsible threading die 10 which is a driven through a belt 11 by a motor 12.

The tap holders 5 and 6 are mounted on suitable guideways on the frame 1 and are moved backward and forward by cylinders 13 and 14,-respectively. Fluid under pressure actuating pistons in these cylinders 13 and 14 is supplied through pipes15 and 16 respectively from any suitable source. The operation of the heads will be described, and since the operation'of one head is identical with that of the other, a description of one will be sufiicient. As shown in Figures 2 and. 8, the cylinder 14 is provided with a piston 17 and a piston rod 18. A /valve 19 in the casing 20 controls the admission of pressure fluid to and exhaust from the cylinder. The valve 19 is operated through a link 21 which is connected witha control rod 22 provided with an operating handle 23.

\Vhen the handle 23 is thrown downwardly as viewed in Figure 2, fluid presure is admitted to cylinder 14 through'the ipe 24, and as the valve for cylinder 13 is slmilarly' actuatedipressure is admitted to cylinder 13 through pipe 25, whereupon the tap holders are moved away from each other.

Mounted in the intermediate portion of ,the frame 1' is a vertical shaft 26 to the upper end of which is keyed the main turret 27, The turret 27, as shown in Figures 1 and 3, is rovided .with four sub-turrets 28, 29, 30 an 31. Each of these sub-turrets isprovided with a conical projection 32 which extends downwardly through an o the turret 27. The openings in t e turret 27 are each provided with a conically shapedbearing member 33 which fits the conical portion '32. The projections on the subning in turrets are also provided with a cylindrical portion 34 to each of which is keyed a Geneva gear element. These gear elements are designated by the reference characters 35, 39, 40 and 41, and are connected to the respective turrets 29, 30, 31 and 28, by washers 36, nuts 37 and jam nuts 38. Each of the sub-turrets 28 to 31 rests upon a circular track or guideway 42 upon the main turret 27. The shaft 26,- to which the main turret 27 is keyed, is provided with a frustoconical portion which engages a bearing member 43 in the frame 1. The upper end of shaft 26 is threaded and provided with collar 44 which is held in place by anut 45 and lock nut 46. On thelower end of shaft '26 a ratchet wheel 48 is mounted-to turn with the shaft and has a hub extension engaging the bearing member 43. The ratchet 48 .is provided with as many teeth as there are sub-turrets mounted on the main turret 27. J ournaled on the hub extension of the ratchet wheel 48 is a pawl carrier 19 which is provided with a gear segment 50, as shown in Figure 7. A'rack 51 is provided with teeth which engage theQteeth on the gear segment 50. The rack is pivotally connected at one end to an arm 114 projecting down- 'wardly from the tap holder 6 whereby movements of the holder back and forth on its guideway are effective to reciprocate the rack. The pawl carrier- 49 is provided with a socket for a pawl 52 and a spring 53 which keeps the pawl normally in engagement with the ratchet wheel 48. The ratchet wheel 48 is held in place by a washer 54, nut 55 and lock nut 56. The rack51 reciprocates against a wear plate 57 which is held in place in a recess in a projection 58 on the-frame 1 by a bolt 59 and nut 60. The wear plate 57 is tapered and may be adjusted to take up any wear which takes place between the rack 51 and the gear segment 50, as shown in Figure 7. 61 is a Geneva gear element fixed. to the frame 1 by a dowel 61. "It surrounds the bearing 43 on shaft 26 and co-acts with the Geneva gear elements on the sub-turrets to rotate said turrets about their axes. The gear element 61 is provided with two cut away portions 62 and 63 for permitting the gear elements 35, 39, 40 and 41 to rotate about their axes when passing such portions. The gear" elements 35,39, 40 and 41 are rotated by the movement of turretv 27 about its axis and fixed pins 64 and 65 which are mounted in the frame in fixed relation to the cut away portions 62 and 63, as shown in Figures 3 and 4, and en age slots in the gearyelements 35, 39, 40 an 41. Each of these gear elements 35, 39, 40 and 41 is provided with four slots 66, 67, 68 and 69, and'every time that the main turret 27 is rotated 90 degrees as hereinafter explained one'of the slots in each of two adjacent gear elements 35, 39, 40 or 41 will be engaged by the-pins 64 afid65, which will rotate said two gear elements together with their sub-turrets .,l80, degrees about their axes for the purPQse-Ehereinafter described.

Mounted upon each of the sub-turrets 28 to31 are identical chucks 70, 71, 72, 7 3, respectively. These chucks operate upon the principle disclosed in my application Serial No. 439,959, filed January 26, 1921. Each of the chucks is provided with a casing 74 of generally cylindrical shape-and provided with a base 75 which rests upon the subturret and which is also provided with a projection 76 which fits in a corresponding depression in the sub-turret. The base 75 may be bolted or otherwise securely fastened to the sub-turret. The casing 7 4 is provided with a central opening into which is fitted a fixed sleeve 77 having a plurality of radial slots 78 in the central portion thereof and in which slots are fitted the jaw members 79. The slots 78 are of such width and length as to permit free movement of the jaw members 79. The sleeve 77 has portions at its ends which are not slotted and which portions are utilized to effectively hold the member 77 in the casing 74. A spring band 80 is arranged, as shown in Figures 5 and 6, and acts normally to hold the gripping members 79 in the retracted or non-gripping position.

Rotatably mounted in the chuck casing 74 are jaw actuating rings 83 and 84. The ring 84 is restrained against rotary movement while the ring 83 is provided with an actuating handle, which extends outwardly through a central slot in the chuck casing. The adjacent faces of rings 83 and 84 are provided with cams which are arranged to spread the rings laterally along the axis of the chuck when ring 83 is rotated in one direction and to permit said rings 'to be moved toward each other when ring 33 is rotated in the opposite direction. The space within the chuck casing 74 and confined by the casing 74, sloping outer faces of rings 83' and 84,0uter faces of jaw members 79 and portions of sleeve 77 is filled with a shiftable non-compressible pressure applying medium such as a plurality of steel balls 82, which acts 1n a manner similar .to a noncompressible liquid. v

Mounted on the guides 89 attached to the frame 1 of the machine, is a centering head 90 which is provided with an expanding chuck, as shown in Figures 3, 5 and 6. This chuck comprises three expansible jaws 91,

normally held in retracted position by a coil spring 92 which surrounds the jaws near one end. A frusto-conical expander 93 is centrally mounted in the centering head and is engaged by the inner faces of aws 91, as

best shown in Figure 6. This expander 93 is provided with a threaded extension 94 en- 1 tion.

gaging a hand wheel 95 having a boss 96 thereon. The boss 96 is provided with an annular slot 97 in which is seated a retainer 98 attached to the head 90 so that upon rotation of the hand wheel -95 in one direction or the other the expander 93 is positively moved toexpand or permit the retraction of the. jaws 91. The screw threaded portionof the projection 9-1 is also provided with lock nuts 99 which limit the movement of the expanding member 93 in one direc- The head 90 may be moved to the position shown in Figures 1 and 3 by means of a treadle 100 through a lever 101. The treadle 100 and lever 101 are keyed to ashaft 102 which is journaled in supports 103 attached to the base of the machine. A spring 104 acts to move the head 90 to the left, as viewed in Figure 3, when the 0 crating pressure is removed from the treadle 100.

Fastened to the control rod 22 is a ratchet segment 105 and 106 is a pawl one end of I which engages the teeth on the segment 105 while the other end is enga ed by a shifter slidably mounted in one 0 the uideways 89 forfl-the centering head. The shifter 107 has "a beveled upper end 108 which is engag'ed- 'by the head 90 when the head is in its retracted position for lifting pawl 106 clear of ratchet segment 105. The arrangement thus described renders it impossible for the operator to actuate the thread milling heads 5-and 6 so long as the head'90 is removed from engagement with the upper end 108 of shifter member 107, or when the centering head is in a chuck. A spring 109 is arranged to hold-the shifter 107 in its raised position when the head is moved inward, as shown in Figure 3.

The tap holders 5 and 6 andthc centering head 90 are provided each with a tongue 110 which is adapted toengage in slots 111 in the sub-turrets 28, 29, 30 and 31 to lock the sub-turrets against any tendency to turn on their axes whenthe tap holdersor the centering head are moved into operative relation to the sub-turrets.

The operation of my device is as follows: For convenience in the description of the operation of the machine, attention is called to Figures 1, 3, 4 and 5, in which dotted lines w, m, y and z in Figure 4 designate the centers of the threading chucks onsubturrets 31, 30, 29' and 28 respectively. The reference letters w, a, y and a, being at the endsof the chucks through which the couplings-to be threaded are inserted for the cy.cle'=,of the machine to be described.

Assuming all of the threading chucks on the sub-turrets to be empty and expanded and the centering head 90 retracted and over 7 the upper end of-shifter 108.

A coupling such as shown at 88 in Figure 5 is put on in the chuck on the centerin head, the centering chuck is then expande threading o to center the coupling with relation to the opening therethrough. The chuck and centered coupling are then moved into the threading chuck 7 3 on turret 31 along the line .412. The threading chuck 73is then contractedto grip the periphery of the coupling and due to its construction the coupling will be fixed in chuck 7 3 in the position held by the centering chuck, regardless of whether the periphery of the coupling is concentric with the opening therethrough. or not; The centering chuck is now collapsed and the centering head returned to its-position over shifter 108 and thereby releases the control rod 22. Control rod 22 is now shifted to cause taps 7 and 10 to be moved toward each other, but as there are no couplings in chucks and 7 2 on sub-turrets 28 and 30, the movement of the taps will be an idle one. In the forward movement of tap holder 6, pawl 52, will be moved back over one tooth on ratchet wheel 48. After ta holders 5 and 6 have been moved to their ull limit toward each other, the operator reverses control rod- 22, to return the tap holders 5 and 6 to the positions show,n.=- in; the drawings. During this return movement of tap holder 6, turret 27 will be rotated 90 degrees in a counterclockwise direction-through the medium of pawl 52 and ratchet wheel 48, and shift the sub-turrets 90 degrees from the positions shown in the drawings. This shifting of the sub-turrets will bring charged threading as shown in Figure 4. The operator now charges threading chuck 72 as above described, repeatsthe operation for threading above described and threads the coupling in chuck 73. During the return movement of the tap holders 5 and 6 in the second cycle, turret 27 will again be shifted 90 degrees, again rotate two of the turrets 18 degrees about their own axes and shift the sub-turrets 90 degrees.

It will therefore been seen,'that after the machine has ,been in operation for three cycles, both taps will thread a coupling when shifted einto threading relation with the couplings inlthe threading chucks, Tap

7 will threadone end of each coupling while tap .10 threadthe. other end of each couplin in-a successivemanner. This the couplings from op osite ends by taps 7 and 10 is accomplished y rotating the sub-turrets 360 degrees on their own axes by pins' 65 and 64, in their movea IIIOIG expe ment from their positions in front of tap 7 to their positions in. front of ta 10.

From the foregoing, it wi be evident that my invention has many advantages, among which may be mentioned that both ends of a coupling or similar article may be automatically threaded without the necessity of a centering operation between each threading'operation; a plurality of articles may be operated upon simultaneously and automatically; by reason of the. arrange ment of the parts, the machine operates in itious manner than any machine heretofore constructed, and the work is turned out in a more accurate form than is the case where a se aratecentering operation is required; both threading operations are'ca rried out with the same centering so that the threads produced are in proper alinement with each other, thus avoiding any possible defect bymisalinement of the threads. Further objects .will be apparent to those skilled in the art.

While. I have described one embodiment of my invention, I do not desire to be limit' ed to the exact arrangement shown. It is sometimes advisable to perform a threading or similar operation at the station y, as, for instance, when .a T-coupling is being acted upon. In suchevent; a third tap holder would be provided at the station y and thearticles so placed upon the sub-turrets that the third portion of the article would be presented radially to the tap holder at the station :1 I therefore desire it to be understood that my invention is broad enough to include that and other. modifications of the 4 specific device shown and described.

A further advantage results from the provision of a method and ap aratus for machining articles whereby t'e article to be machined is centered with relation to the machine tools, secured in such centered position, the centering means being then removed and the article and machine tool are then moved into machining relation.

By the use of such an apparatus I am enabled to chuck articles having openings therein which are to be machined, by first centering the opening on the centering chuck and then chucking the artiole in its centered position, regardless of the exterior contour. This eliminates the'cutting away of surplus .metal if the opening is not'central of the article, and also insures a fully machined; face.

I claim: l

1. The method of machining difierent portions of an article, comprising centering the article on a carrier, moving a machining tool and the article relative to each other to machine one portion thereof, and moving the article on the carrier to brin another portion of the article into machining osition relative to a second tool, and t en chining operations on an article, the steps of centering an article on an axis about which it is to be moved, bringing the article and a machining toolinto machining relation and machining one ortion of the article,

then rotating the article about the axis on which it is centered to shift the machined portion of the article and bring another portion of the article into machining position and moving the article and first axis about a second axis to bring thesecond portion of the article into machining relation to a second machining tool, and then machining the second portion of the article.

3. In the method of successively machining two surfaces of an article, machining a5 articles-in a successive manner and simultaneously machining a portion of two articles, the steps of successively centering the articles to be machined on axes movable' about another axis, successivelv bringing 00 each article so centered into machining relation to two machining tools as the articles are moved about said axis, rotating each article for a portion of a cycle about the axis on which it is centered after the first machining and before the second machining, and simultaneousl moving both machining tools into machining relation to two articles whereby one portion of each article is" machined byone tool and the other por-- tion by another tool.

4. In the method of successively threading pipe fittings havin two separately threaded portlons 'an simultaneously threading a portion of two fittings, the

steps of successively centering the fittings on successive movable axes rotatable about a fixed axis, with the axes of the bores in' the fittings 'normal to the movable axes. and in the plane of the axes of two threading tools, moving the fittings in a step by step manner after centering t0 the threading tools, simultaneously moving the threading tools into threading relation with different fittings, and successively lo tating the fittings about the movable axes on which thevare centered while moving 'said fittings about the fixed axis from one threading tool to the other threading tool.

5. In the method of successively threading pipe couplings from opposite ends, the stepsof successively centering the openings in the couplings on movable axes. rotatable about a fixed axis, with the axes of the openings in the couplings normal to .the

movable axes and in the plane of the axes of two threading tools, moving the fittings in a step by step manner after centering to the threading tools, simultaneously moving the threading tools into threading relation faces of articles, the steps 'of engaging the surface to be machined by a centering chuck .whose center is in the plane of the center of the machining tool for finishing such sur-- faces, securing the article to a holder in such centered position, removing the cen- .tering chuck, and then moving, the mashiningtool and article into machining relation and machining said surface. J

7. In the method of threading pi e fittings, the steps of engaging the sur ace to be threaded by-a centering chuck whosc center is in the plane of the center of a thread- I ing tool for finishing such surface, securing the pipe fitting to a holder in such cen tered position, removin chuck, and then moving t e threading tool and; article into, threading relation and ,threadin "such surface.

8. In ings of pipe fittings, the steps of enga 'ng I the wall. of the o ening to be machine by a centerin chuc whose center is in the plane of t e center "of the threading tool,

securing the fittin to a holder in such posi: .tion, removin v t e centering chuck, and then moving t e threading tool and the fitting into threading relation .and threading the o ening in'the fitting;

9. n. the method ofthreading the interior of pipe couplings from both ends, the steps 'of engaging the wall ofthe opening through the couplingby a centering chuck whose 'center 1s in'the plane, of two threading dies, securing the article in a holder in;such centered position, removing the centering chuck, and then moving the couplin first 4i into threading engagement with" one t reading die and then with another threading y con lings, the steps of engaging the we 10. In the' method er threading pigs. 0 through the coupling by a centering e uckwhose center is in the plane of the' center of twothreading dies, securing the coupling to a holder "in such centered position, removing the centerin chuck, then moving a threading die into t reading relation with one end of the. coupling, then: moving the coupling into threading relation with the: second threading die and turning the coupling end forend after the first threading ope a n ee' ei et e ewn t ea es the centering e' method of threading the openoft e A hand.

jeration, and then'threading the other end-of the coupling with a second die.

ll. A device of the'characterdescribed having an article holder, a centering chuck,

means for'moving the centering chuck toward and from the article holder, means on the article holder for securing the article in a positionxcentered by the chuck, and a ma- I chining tool for machining the centered surface.

12. A machine of the character described having a main turret a lurality of sub-turrets mounted on the mam turret, a radially disposed centering chuck, means for moving the centering chuck toward and from the sub-turrets, a holding chuck on each of the sub-turrets for holdin the article in the position centered by the centering chuck,- anda machining tool forymachining the centered surface.

comprising a main turret, a plurality of 13. A machine for threading-pipe fittingssub-turrets mounted on the main-'- turret, a

hydraulic chuck on each sub-turret arranged to grasp the exterior of a pipefittmg, a centering chuck arranged to engage the walls.

of an opening in a pipe fitting for centering i the opening with relation: to the centering chuck, means ,for moving the centering chuck to position the centered fittin into a holding chuck on a sub-turret, a 1iurahty the threading dies-into andout' of, couplings in the chucks, and meansfor rotatmg the sub-turrets when the mainturret is rotated .ofzthreading dies radially disposed with re-" lation to the main turret, means*for movmg to shiftfthe'sub turrets from one'threading:

die tditheother.

14. A machine for threading pipe couplings comprising a rotatable main .turret,. a glurality of sub-turrets rotatably mounte on the main turret, a hydraulic chuck on each sub-turret arranged to engage the outer su-r-.

face of a pipe turret, a centering chuck arranged to en age coupling, two threading dies radially disposed with relation to the'main the walls of-the opening through acoup 'ng and hold it in a position centered relative to the centering chuck and in the-plane of the threadin dies, means for'movin' the center ing chuc togetherwith the coup ing thereon within av chuck on a sub-turret, means-:for simultaneously moving the threading dies into two cou lings in chucks on sub-turrets, and means or turning the sub-turrets 360 degrees in their movement from one thread-.

in die to the other.

i n testimony whereof I hereunto set my cr a e arlena 

